Scientists hail spinal injury breakthrough

A pioneering technique that uses the body's nerves to bypass spinal injuries could help thousands of people to regain feeling, and possibly even the use of paralysed limbs, scientists say. Using similar principles to heart bypass surgery, where veins from a patient's leg are used to get around an artery blockage, scientists in the US have shown that nerves can be used to circumvent spinal damage and reconnect the brain to the body.

The procedure, successfully used in experiments with rats, raises the prospect of the first human trials within five years, offering hope to the 40,000-plus people in the UK with spinal cord injuries.

Researchers know that the part of the spine below an injury is often capable of responding to electrical signals, but because it is isolated from the brain it cannot control anything.

According to a report in New Scientist today, in experiments on rats with spinal injuries, a team led by John Martin, a neuroscientist at Columbia University in New York, cut away a nerve from just above the injury that normally stretches into the body to control abdominal muscles and reattached it to the spine below the injury. The rats went on to show an increase in movements of previously-paralysed limbs, Martin told a meeting of the New York state spinal cord injury research programme.

"What we've documented is that we've reconnected the nervous system above the injury with below the injury in a robust way," Martin told the Guardian. He said it was particularly encouraging that nerves which control movement were able to regenerate quite effectively within the spinal cord, by contrast with nerve cells which control sensation or feeling.

When the nerves were reattached to the spinal cord they grew well and returned some function to the body. "The hope is to try to overcome some of the paralysis."

Reconnecting a single nerve would not be sufficient to reactivate all of a patient's lost functions, and the patient would have to decide with their doctor what was most important to improve their quality of life. Martin said: "For example, in a quadriplegic with limited upper extremity mobility, increasing the strength of shoulder muscles is very helpful because that could help their transfer from a wheelchair to a bed or toilet - it gives them independence."

A leading UK neuroscientist, Patrick Anderson, professor of experimental neuroscience at University College London, said the findings were exciting, but cautioned that there was still much research to be done before the technique could be tried in humans.

Anderson, who was not involved in the research, said: "It's quite an exciting response, it's novel and no one's achieved quite that before.

"The exciting thing is that it's got some distinct physiological evidence for functional circuits being formed. Whether that would enable an animal to consciously produce a movement they wanted is guesswork."

Scientists have previously tried nerve bypass operations in rats, but the results have never been promising: experiments in the early 1980s showed that nerves removed from rats' legs and used to bypass a spinal injury did not grow well enough to be useful in their new location.

The technique would need much more development, Martin admitted, but if all went well - and because it employed surgical techniques already commonly used by doctors - trials in humans could start in as little as five years.

Mark Bacon, head of research for the International Spinal Research Trust, said: "While this sort of thing is very encouraging, we have to temper enthusiasm about the immediate relevance to humans. The systems involved in control of locomotion in one species [rats] are subtly, but importantly, different from those in humans."

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